TOKYO - Japan's Liberal Democratic Party (LDP) Secretary-General Hiroshi Moriyama has announced his intention to step down to take responsibility for the party's crushing defeat in the Upper House election, local media reported.

Moriyama is expected to submit his resignation to Prime Minister and LDP President Shigeru Ishiba, according to Mainichi newspaper.

His resignation is seen as a major blow to party management, with many within the LDP warning it could stall the government's ability to function and increase pressure on Ishiba himself to decide his own political future.

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Ishiba on Tuesday said he will make a decision on whether to resign at an appropriate time.

At the Liberal Democratic Party's (LDP) joint general assembly, Ishiba said he had no intention of clinging to his position. "My duty is not to evade responsibility, but to make the proper decision at the proper time."

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He highlighted priorities including ensuring wage growth above inflation, negotiating tariffs and strengthening the economy, and reforming agricultural policy such as rice support measures, national broadcaster NHK reported.